1. Field of the Invention
The present invention relates to a pneumatic sanding machine, and more particularly to a pneumatic sanding machine that has a control valve that changes movement of exhausting compressed air so that the sanding machine provides a selectable way of dealing with wood-dust or sanding debris caused during sanding.
2. Description of Related Art
Sanding machines, as known as sanders are used to smooth work-pieces, such as wood. A pneumatic sanding machine applies compressed air or pressurized air as a power to actuate the sanding machine working. When a person uses a pneumatic sanding machine to make something smooth, dust and debris will be produced by the sanding operation.
There are three operations introduced into the sanding machines in accordance with the prior art, one of which is not to deal with the dust, the second is to collect the dust into a dust bag and the third way is to vacuum the dust into a vacuum cleaner regarded as a central-aspirated feature. However, each of the stand-alone sanding machines in accordance with the prior art provides only one of the three operation ways to deal with the powder. None of the conventional sanding machines provides all three operation ways such that a person who is using the sanding machine can select a proper way to deal with the dust. Besides, the last two of the aforementioned operations for dealing with the dust involves a lot of parts assembled in the sanding machine and assembly of these parts into the sanding machine requires excessive time. Consequently, the conventional sanding machine is not only inconvenient to use but also involves uneconomic fabrication costs.
To overcome the shortcomings, the present invention provides a sanding machine having a control valve that changes a movement of exhausting compressed air so that a way to deal with the waste material is selectable to mitigate or obviate the aforementioned problems.